Advancing Newborn Screening Long-Term Follow-Up: Integration of Epic-Based Registries, Dashboards, and Efficient Workflows

The Connecticut Newborn Screening (NBS) Network, in partnership with the Connecticut Department of Public Health, strategically utilized the Epic electronic health record (EHR) system to establish registries for tracking long-term follow-up (LTFU) of NBS patients. After launching the LTFU registry in 2019, the Network obtained funding from the Health Resources and Services Administration to address the slow adoption by specialty care teams. An LTFU model was implemented in the three highest-volume specialty care teams at Connecticut Children's, involving an early childhood cohort diagnosed with an NBS-identified disorder since the formation of the Network in March 2019. This cohort grew from 87 to 115 over the two-year project. Methods included optimizing registries, capturing external data from Health Information Exchanges, incorporating evidence-based guidelines, and conducting qualitative and quantitative evaluations. The early childhood cohort demonstrated significant and sustainable improvements in the percentage of visits up-to-date (%UTD) compared to the non-intervention legacy cohort of patients diagnosed with an NBS disorder before the formation of the Network. Positive trends in the early childhood cohort, including %UTD for visits and condition-specific performance metrics, were observed. The qualitative evaluation highlighted the achievability of practice behavior changes for specialty care teams through responsive support from the nurse analyst. The Network's model serves as a use case for applying and achieving the adoption of population health tools within an EHR system to track care delivery and quickly fill identified care gaps, with the aim of improving long-term health for NBS patients.

Assessment of Epithelial Lining Fluid Partitioning of Systemically Administered Monoclonal Antibodies in Rats

For systemically administered monoclonal antibodies (mAbs) with pharmacological targets in the epithelial lining fluid (ELF), information on the partitioning of mAb between plasma and ELF is instrumental for dose predictions. Bronchoalveolar lavage (BAL) combined with measurements of urea as indicator of sample dilution is often used to estimate ELF concentrations of a drug. However, unbalanced extraction of mAb and urea could potentially lead to a systematic bias in the back-calculated ELF concentration. In the present study 0.5, 1, or 4 mL phosphate-buffered saline was instilled to lungs of rats to obtain lavage samples after systemic dosing of mAb and tool small molecule (n≥4/group). Furthermore, extraction of urea, mAb and the small molecule was assessed by repeatedly lavaging the lung (n = 4). There was no statistically significant difference in the calculated partitioning into ELF between the evaluated instillation volumes. Repeated BAL demonstrated that urea and the small molecule were extracted from other sources than the ELF. In contrast, there was limited to none in-flow of mAb into the lavage fluid. The unbalanced extraction of urea and mAb could theoretically result in underestimated ELF concentrations and the calculated partitioning of 0.17±0.062 might therefore constitute a lower boundary for the true partitioning.

Prevention of Growth Failure in Turner Syndrome: Long-Term Results of Early Growth Hormone Treatment in the "Toddler Turner" Cohort

INTRODUCTION

In the randomized "Toddler Turner" study, girls who received growth hormone (GH) starting at ages 9 months to 4 years (early-treated [ET] group) had marked catch-up growth and were 1.6 ± 0.6 SD taller than untreated (early-untreated [EUT]) control girls after 2 years. However, whether the early catch-up growth would result in greater near-adult height (NAH) was unknown. Therefore, this extension study examined the long-term effects of toddler-age GH treatment on height, pubertal development, and safety parameters.

METHODS

Toddler Turner study participants were invited to enroll in a 10-year observational extension study for annual assessments of growth, pubertal status, and safety during long-term GH treatment to NAH for both ET and EUT groups.

RESULTS

The ET group was taller than the EUT group at all time points from preschool to maturity and was significantly taller at the onset of puberty (p = 0.016), however, the difference was not significant at NAH. For the full cohort (ET + EUT combined, n = 50) mean (± SD) NAH was 151.2 ± 7.1 cm at age 15.0 ± 1.3 years. NAH standard deviation score (SDS) was within the normal range (>-2.0) for 76% of ET and 60% of EUT subjects (68% overall) and correlated strongly with height SDS at GH start (r = 0.78; p < 0.01), which in turn had a modest inverse correlation with age at GH start (i.e., height SDS declined with increasing age in untreated girls [r = -0.30; p = 0.016]). No new safety concerns arose.

CONCLUSION

Although the ET group was taller throughout, height SDS at NAH was not significantly different between groups due to catch-down growth of ET girls during lapses in GH treatment after the Toddler study and similar long-term GH exposure overall. Early initiation of GH by age 6 years, followed by uninterrupted treatment during childhood, can prevent ongoing growth failure and enable attainment of height within the normal range during childhood, adolescence, and adulthood.

Impact of Pediatric Electronic Consultations in a Federally Qualified Health Center

Background: Access to pediatric specialty care is a challenge, particularly for medically underserved populations. Introduction: One evolving method that has shown promise in helping ameliorate this disparity is electronic consultations (e-consults). Materials and Methods: This retrospective cohort study compared two groups: patients referred to pediatric cardiology, endocrinology, or pulmonology from a Federally-Qualified Health Center 10 months before the implementation of an evidence-based care pathway and those referred in the 10 months after implementation. The care pathway included evidence-based referral guidelines for common pediatric diagnoses and an e-consult process. Data included patient demographics, dates of referral requests, appointment dates, e-consult response dates and times, diagnosis codes, and consultants' recommendations. Results: Twenty-three percent of all referrals made postimplementation were submitted for an e-consult, with 53% preventing an unnecessary face-to-face visit. The most common reason for an e-consult was heart murmur/chest pain for cardiology, short stature for endocrinology, and asthma for pulmonology. Discussion: Providers used e-consults for nearly one-quarter of all consultations postimplementation, resulting in 17% of consultations not needing a face-to-face visit. The use of e-consults combined with evidence-based referral guidelines provided a useful tool to help front line pediatric primary care providers manage complex problems and identify those not needing to see a specialist in person. Conclusions: Evidence-based care pathways combined with e-consults can help improve access to pediatric specialty care by reducing demand for in-person visits and allowing more care to be delivered in primary care.

The Turner syndrome research registry: Creating equipoise between investigators and participants

To address knowledge gaps about Turner syndrome (TS) associated disease mechanisms, the Turner Syndrome Society of the United States created the Turner Syndrome Research Registry (TSRR), a patient-powered registry for girls and women with TS. More than 600 participants, parents or guardians completed a 33-item foundational survey that included questions about demographics, medical conditions, psychological conditions, sexuality, hormonal therapy, patient and provider knowledge about TS, and patient satisfaction. The TSRR platform is engineered to allow individuals living with rare conditions and investigators to work side-by-side. The purpose of this article is to introduce the concept, architecture, and currently available content of the TSRR, in anticipation of inviting proposals to utilize registry resources.

Pediatric endocrine society survey of diabetes practices in the United States: What is the current state?

BACKGROUND

The Practice Management Committee (PMC) of the Pediatric Endocrine Society (PES) conducted a survey of its membership in February/March, 2016 to assess the current state of pediatric diabetes care delivery across multiple practice types in the United States.

METHODS

The PES distributed an anonymous electronic survey (Survey Monkey) via email to its membership and requested that only one survey be completed for each practice.

RESULTS

Ninety-three unique entries from the US were entered into analysis. Care is predominantly delivered by multidisciplinary teams, based at academic institutions (65.6%), with >85% of the provider types being physicians. Each 1.0 full time equivalent certified diabetes educators serves on average 367 diabetic youth. Fee-for-service remains the standard method of reimbursement with 57% of practices reporting financial loss. Survey respondents identified under-reimbursement as a major barrier to improving patient outcomes and lack of behavioral health (BH) providers as a key gap in services provided.

CONCLUSIONS

Our survey reveals wide variation in all aspects of pediatric diabetes care delivery in the United States. Pediatric Endocrinologists responding to the survey identified a lack of resources and the current fee for service payment model as a major impediment to practice and the lack of integrated BH staff as a key gap in service. The respondents strongly support its organizations' involvement in the dissemination of standards for care delivery and advocacy for a national payment model aligned with chronic diabetes care in the context of our emerging value-based healthcare system.

Standardizing Clinically Meaningful Outcome Measures Beyond HbA1c for Type 1 Diabetes: A Consensus Report of the American Association of Clinical Endocrinologists, the American Association of Diabetes Educators, the American Diabetes Association, the Endocrine Society, JDRF International, The Leona M. and Harry B. Helmsley Charitable Trust, the Pediatric Endocrine Society, and the T1D Exchange

OBJECTIVE

To identify and define clinically meaningful type 1 diabetes outcomes beyond hemoglobin A1c (HbA1c) based upon a review of the evidence, consensus from clinical experts, and input from researchers, people with type 1 diabetes, and industry. Priority outcomes include hypoglycemia, hyperglycemia, time in range, diabetic ketoacidosis (DKA), and patient-reported outcomes (PROs). While priority outcomes for type 1 and type 2 diabetes may overlap, type 1 diabetes was the focus of this work.

RESEARCH AND METHODS

A Steering Committee-comprising representatives from the American Association of Clinical Endocrinologists, the American Association of Diabetes Educators, the American Diabetes Association, the Endocrine Society, JDRF International, The Leona M. and Harry B. Helmsley Charitable Trust, the Pediatric Endocrine Society, and the T1D Exchange-was the decision-making body for the Type 1 Diabetes Outcomes Program. Their work was informed by input from researchers, industry, and people with diabetes through Advisory Committees representing each stakeholder group. Stakeholder surveys were used to identify priority outcomes. The outcomes prioritized in the surveys were hypoglycemia, hyperglycemia, time in range, DKA, and PROs. To develop consensus on the definitions of these outcomes, the Steering Committee relied on published evidence, their clinical expertise, and feedback from the Advisory Committees.

RESULTS

The Steering Committee developed definitions for hypoglycemia, hyperglycemia, time in range, and DKA in type 1 diabetes. The definitions reflect their assessment of the outcome's short- and long-term clinical impact on people with type 1 diabetes. Knowledge gaps to be addressed by future research were identified. The Steering Committee discussed PROs and concluded that further type 1 diabetes-specific development is needed.

CONCLUSIONS

The Steering Committee recommends use of the defined clinically meaningful outcomes beyond HbA1c in the research, development, and evaluation of type 1 diabetes therapies.

Clinical practice guidelines for the care of girls and women with Turner syndrome: proceedings from the 2016 Cincinnati International Turner Syndrome Meeting

Turner syndrome affects 25-50 per 100,000 females and can involve multiple organs through all stages of life, necessitating multidisciplinary approach to care. Previous guidelines have highlighted this, but numerous important advances have been noted recently. These advances cover all specialty fields involved in the care of girls and women with TS. This paper is based on an international effort that started with exploratory meetings in 2014 in both Europe and the USA, and culminated with a Consensus Meeting held in Cincinnati, Ohio, USA in July 2016. Prior to this meeting, five groups each addressed important areas in TS care: 1) diagnostic and genetic issues, 2) growth and development during childhood and adolescence, 3) congenital and acquired cardiovascular disease, 4) transition and adult care, and 5) other comorbidities and neurocognitive issues. These groups produced proposals for the present guidelines. Additionally, four pertinent questions were submitted for formal GRADE (Grading of Recommendations, Assessment, Development and Evaluation) evaluation with a separate systematic review of the literature. These four questions related to the efficacy and most optimal treatment of short stature, infertility, hypertension, and hormonal replacement therapy. The guidelines project was initiated by the European Society for Endocrinology and the Pediatric Endocrine Society, in collaboration with The European Society for Pediatric Endocrinology, The Endocrine Society, European Society of Human Reproduction and Embryology, The American Heart Association, The Society for Endocrinology, and the European Society of Cardiology. The guideline has been formally endorsed by the European Society for Endocrinology, the Pediatric Endocrine Society, the European Society for Pediatric Endocrinology, the European Society of Human Reproduction and Embryology and the Endocrine Society. Advocacy groups appointed representatives who participated in pre-meeting discussions and in the consensus meeting.

Fertility Preservation in Women with Turner Syndrome: A Comprehensive Review and Practical Guidelines

In this article we review the existing fertility preservation options for women diagnosed with Turner syndrome and provide practical guidelines for the practitioner. Turner syndrome is the most common sex chromosome abnormality in women, occurring in approximately 1 in 2500 live births. Women with Turner syndrome are at extremely high risk for primary ovarian insufficiency and infertility. Although approximately 70%-80% have no spontaneous pubertal development and 90% experience primary amenorrhea, the remainder might possess a small residual of ovarian follicles at birth or early childhood. The present challenge is to identify these women as early in life as is possible, to allow them to benefit from a variety of existing fertility preservation options. To maximize the benefits of fertility preservation, all women with Turner syndrome should be evaluated by an expert as soon as possible in childhood because the vast majority will have their ovarian reserve depleted before adulthood. Cryopreservation of mature oocytes and embryos is a proven fertility preservation approach, and cryopreservation of ovarian tissue is a promising technique with a growing number of live births, but remains investigational. Oocyte cryopreservation has been performed in children with Turner syndrome as young as 13 years of age and ovarian tissue cryopreservation in affected prepubertal children. However, current efficacy of these approaches is unknown in this cohort. For those who have already lost their ovarian reserve, oocyte or embryo donation and adoption are strategies that allow fulfillment of the desire for parenting. For those with Turner syndrome-related cardiac contraindications to pregnancy, use of gestational surrogacy allows the possibility of biological parenting using their own oocytes. Alternatively, gestational surrogacy can serve to carry pregnancy resulting from the use of donor oocytes or embryos, if needed.

Effect of myocardial dysfunction in cardiac morbidity and all cause mortality in childhood cancer subjects treated with anthracycline therapy

BACKGROUND

Subacute cardiotoxicity, consisting of acute myocyte damage and associated left ventricular dysfunction, occurs early during anthracycline therapy. We investigated the impact of myocardial dysfunction, defined herein by a shortening fraction (SF) < 29 % at any time during or after anthracycline therapy, on late onset cardiomyopathy and all-cause mortality, among childhood cancer survivors exposed to anthracyclines. In addition, we sought to identify subpopulations of subjects at highest risk for cardiomyopathy and death from all causes.

METHODS

Five hundred thirty-one childhood cancer survivors exposed to anthracyclines were enrolled and studied on average 10 (1.4-27.3) years following their initial exposure. The medical records were reviewed to identify known risk factors associated with cardiotoxicity, including cumulative anthracycline dose, length of post-therapy interval, administration of other cardiotoxic medications (vinca alkaloids), previous heart disease, radiation dose to the heart, history of bone marrow transplantation, age at treatment, gender, systolic dysfunction, and history of congestive heart failure during anthracycline therapy.

RESULTS

Ninety subjects (16.9 %) developed SF < 29 % and 71 patients (13.4 %) died on average 10 years after initial exposure (range 1.4-27.3 years). Total cumulative dose (OR 3.27, 95 % CI 1.94, 5.49, p < 0.001) and bone marrow transplantation (OR 2.57, 95 % CI 1.24, 5.30, p = 0.01) were found to be statistically significant risk factors for development of myocardial dysfunction. There was a 3-fold increase in the odds of having a SF < 29 % at any point during or following cancer therapy if a subject underwent bone marrow transplantation or had a total cumulative dose anthracycline therapy ≥ 240 mg/m². The all-cause mortality ratio was almost seven-fold higher (95 % CI, 2.40-fold to 17.81-fold higher) if a subject developed systolic dysfunction, defined by a previous SF < 29 % anytime during or after anthracycline therapy. Nine deaths (12.7 %) were attributed to cardiovascular disease. The risk of dying as a result of cardiac disease also was significantly higher in individuals who had a SF < 29 % at any time during or after therapy.

CONCLUSIONS

This study demonstrates an almost seven-fold increase in all cause mortality in pediatric cancer survivors with a history of anthracycline induced myocardial dysfunction defined as SF < 29 %.

Impact of Co-management at the Primary-Subspecialty Care Interface on Follow-up and Referral Patterns for Patients With Concussion

BACKGROUND

Co-management is a collaborative care model that consists of structured tools to define and document care delivered by 2 or more providers. We evaluated the impact of implementing co-management at the interface between pediatric primary care providers (PCPs) and subspecialists.

METHODS

Participating PCPs (n = 9) were trained on management of concussion using the co-management tools. Co-managed patients with concussion were prospectively enrolled (n = 148) and compared to a retrospective audit of non-co-managed patients (n = 50).

RESULTS

PCPs using co-management demonstrated adherence to the tools. PCPs were significantly more likely to provide follow-up care to patients when using the co-management tools. All participating PCPs reported that co-management enhanced their expertise in caring for patients with concussion.

CONCLUSIONS

Co-management can enhance PCPs' capacity to independently manage the care of patients with concussion. Co-management led to an observed change in practice that merits further exploration in terms of cost, quality, and clinical outcomes.

Commentary: Launch of a quality improvement network for evidence-based management of uncommon pediatric endocrine disorders: Turner syndrome as a prototype

BACKGROUND

Traditional, hypothesis-oriented research approaches have thus far failed to generate sufficient evidence to achieve consensus about the management of children with many endocrine disorders, partly because of the rarity of these disorders and because of regulatory burdens unique to research in children.

OBJECTIVE

The Pediatric Endocrine Society is launching a quality improvement network in spring 2015 for the management of pediatric endocrine disorders that are relatively uncommon in any single practice and/or for which there is no consensus on management.

DESIGN

The first of the quality improvement programs to be implemented seeks to improve the care of 11- to 17-year-old girls with Turner syndrome who require initiation of estrogen replacement therapy by providing a standardized clinical assessment and management plan (SCAMP) for transdermal estradiol treatment to induce pubertal development. The SCAMP algorithm represents a starting point within current best practice that is meant to undergo refinement through an iterative process of analysis of deidentified data collected in the course of clinical care by a network of pediatric endocrinologists.

CONCLUSION

It is anticipated that this program will not only improve care, but will also result in actionable data that will generate new research hypotheses and changes in management of pediatric endocrine disorders.

Implementation of referral guidelines at the interface between pediatric primary and subspecialty care

BACKGROUND

In pediatric medicine, inadequate access to subspecialty care is widespread. Referral Guidelines are structured tools that describe criteria for subspecialty referral and may decrease medically unnecessary referrals and thereby improve access.

PROBLEM

Variation in referral rates and suboptimal communication around pediatric subspecialty referrals leads to inappropriate and ineffective use of scarce clinical resources.

GOALS

Connecticut Children׳s Medical Center prioritized the development of collaborative care tools at the interface between primary and subspecialty care, including Referral Guidelines.

STRATEGY

A comprehensive set of Referral Guidelines was developed and consisted of background information on a given condition, strategies for initial evaluation and management, instructions for how and when to refer, and what the patient and family could expect at the visit with the subspecialist. A key component of the initiative was the integral role of the PCP during development.

RESULTS

Twenty-eight Referral Guidelines have been developed among 15 subspecialty areas. A novel process for active dissemination of Referral Guidelines was piloted in one medical subspecialty area and led to a reduction in overall referrals and an increase in the proportion of referrals meeting the necessary criteria.

Lowered albumin extravasation rate in heart but not in other organs in beta3-integrin-deficient mice

AIM

The vascular protein permeability is dependent on the integrity of the vascular wall. The heart capillaries in male mice lacking beta3 integrins have an immature phenotype. Previously, we have demonstrated a role for alphavbeta3 integrins in control of interstitial fluid pressure (Pif) and thereby in the fluid flux during inflammation. We wanted to explore a possible role for alphavbeta3 integrins in controlling capillary protein permeability during control situation and inflammation.

METHODS

We performed double-tracer and microdialysis experiments on beta3-integrin-deficient mice and wild type control mice. We also measured blood pressure and heart rate in the two mice strains.

RESULTS

We found reduced albumin extravasation (during 25 min) in the heart capillaries (0.053 +/- 0.003 vs. 0.087 +/- 0.009 mL g(-1) dw, P < 0.05), and an increased cardiac mass/body weight (5.3 x 10(-3) +/- 0.3 x 10(-3) vs. 3.8 x 10(-3) +/- 0.1 x 10(-3), P < 0.01) in the beta3-integrin-deficient mice (n = 6) compared with the controls (n = 6). Heart rate and blood pressure were the same in mice with and without beta3-integrins. No difference in permeability was found in other tissues studied, or under local inflammation.

CONCLUSION

These results show a function for the alphavbeta3 integrin in the regulation of protein permeability, selective for the heart capillaries.

High‐dose, short‐term, anti‐inflammatory treatment with dexamethasone reduces growth and augments the effects of 5‐fluorouracil on dimethyl‐α‐benzanthracene‐induced mammary tumors in rats

OBJECTIVE

To evaluate the effects of dexamethasone (DXM) alone or in combination with 5-fluorouracil (5-FU) on dimethyl-alpha-benzanthracene (DMBA)-induced mammary tumors in rats.

MATERIAL AND METHODS

Female Sprague-Dawley rats were divided into 4 groups receiving: 1) saline (controls), 2) DXM (3 mg/kg), 3) 5-FU (1.5 mg/kg) and 4) DXM and 5-FU combined. The drugs were given i.p. every day for 4 days. Interstitial fluid pressure (Pif) and tumor growth were determined in all tumors on days 1, 5 and 7 using the "wick-in-the needle" technique and by external size measurements, respectively. Vessel density and inflammatory cell infiltration of tumor tissue were analyzed by immunohistochemistry.

RESULTS

DXM treatment significantly retarded tumor growth and reduced Pif. Treatment with a combination of DXM and 5-FU reduced tumor size significantly more than any of the agents alone (p<0.01-0.001). Enhanced uptake of 5-FU by DXM treatment was demonstrated by microdialysis. There were no differences in the density of CD31-positive vessels after DXM or 5-FU treatment, but inflammatory cell infiltration of tumor tissue was significantly reduced after DXM treatment.

CONCLUSIONS

Our data suggest that DXM may be beneficial as an adjuvant to chemotherapy in the treatment of mammary cancer by increasing the uptake of 5-FU in the tumor.

Growth hormone treatment of early growth failure in toddlers with Turner syndrome: a randomized, controlled, multicenter trial

CONTEXT

Typically, growth failure in Turner syndrome (TS) begins prenatally, and height sd score (SDS) declines progressively from birth.

OBJECTIVE

This study aimed to determine whether GH treatment initiated before 4 yr of age in girls with TS could prevent subsequent growth failure. Secondary objectives were to identify factors associated with treatment response, to determine whether outcome could be predicted by a regression model using these factors, and to assess the safety of GH treatment in this young cohort.

DESIGN

This study was a prospective, randomized, controlled, open-label, multicenter clinical trial (Toddler Turner Study, August 1999 to August 2003).

SETTING

The study was conducted at 11 U.S. pediatric endocrine centers.

SUBJECTS

Eighty-eight girls with TS, aged 9 months to 4 yr, were enrolled.

INTERVENTIONS

Interventions comprised recombinant GH (50 mug/kg.d; n = 45) or no treatment (n = 43) for 2 yr.

MAIN OUTCOME MEASURE

The main outcome measure was baseline-to-2-yr change in height SDS.

RESULTS

Short stature was evident at baseline (mean length/height SDS = -1.6 +/- 1.0 at mean age 24.0 +/- 12.1 months). Mean height SDS increased in the GH group from -1.4 +/- 1.0 to -0.3 +/- 1.1 (1.1 SDS gain), whereas it decreased in the control group from -1.8 +/- 1.1 to -2.2 +/- 1.2 (0.5 SDS decline), resulting in a 2-yr between-group difference of 1.6 +/- 0.6 SDS (P < 0.0001). The baseline variable that correlated most strongly with 2-yr height gain was the difference between mid-parental height SDS and subjects' height SDS (r = 0.32; P = 0.04). Although attained height SDS at 2 yr could be predicted with good accuracy using baseline variables alone (R(2) = 0.81; P < 0.0001), prediction of 2-yr change in height SDS required inclusion of initial treatment response data (4-month or 1-yr height velocity) in the model (R(2) = 0.54; P < 0.0001). No new or unexpected safety signals associated with GH treatment were detected.

CONCLUSION

Early GH treatment can correct growth failure and normalize height in infants and toddlers with TS.

A workshop on pubertal hormone replacement options in the United States

BACKGROUND

The optimal pubertal hormone replacement therapy in females and males is unclear.

OBJECTIVE

To review hormone replacement options for hypogonadal teenagers and to determine the relevant attitudes and practices of pediatric endocrinologists in the United States.

DESIGN/METHODS

A workshop on pubertal hormone replacement options was held during the Lawson Wilkins Pediatric Endocrine Society meeting in 2004. A questionnaire was distributed to investigate the audience's attitudes and practices in inducing puberty.

RESULTS

The majority of respondents used conjugated estrogens to treat hypogonadal girls with the primary aim of treatment being attainment of maximal adult height. The majority of respondents used depot testosterone to treat hypogonadal boys with the primary aim of treatment being pubertal development and virilization.

CONCLUSIONS

The use of physiological sex hormone replacement to optimize the induction of puberty in hypogonadal adolescents was recommended. The workshop revealed striking differences between US and European pediatric endocrinologists regarding their practices and attitudes regarding the induction of puberty in hypogonadal females. Detailed studies are necessary to develop more uniform guidelines.

Hypogonadism in adolescent females: new insights and rationale supporting the use of physiologic regimens to induce puberty

Puberty in girls begins with nocturnal pulsatile gonadotropin releasing hormone (GnRH) secretion which increases gradually over a 4 year period and occurs throughout the day. Pulsatile GnRH secretion stimulates pituitary luteinizing hormone (LH) and follicle stimulating hormone (FSH) which induces gonadal steroid secretion, ovulation and oogenesis. Over the past decade, naturally occurring genetic mutations have been identified in a number of genes that impact the onset and progression of puberty and continued progress in this area will lead to earlier diagnosis of hypogonadotropic hypogonadism (HypoH) and potentially improved therapeutic options. Data are accumulating to support the use of more physiological hormone regimens to induce puberty. In addition, our better understanding of how estrogen interacts with the growth hormone - insulin-like growth factor-1 (GH-IGF-1) axis and of differential effects of oral versus non-oral estrogen on various biological parameters have important therapeutic implications for the management of hypogonadal adolescent girls. These implications will be addressed.

Transitioning the patient with Turner's syndrome from pediatric to adult care

The level of medical and neuropsychological complexity throughout the life span of a patient with Turner's syndrome (TS) provides the rationale for a more structured transition from pediatric to adult health care. During late adolescence, the focus of care shifts from maximizing final adult height to completing feminization with estrogen therapy, detecting early antecedents of associated adult conditions, implementing needed therapeutic lifestyle changes, and assessing psychobehavioral risk. An increased prevalence of the dysmetabolic syndrome and osteoporosis is observed in TS. The prevention of obesity and assurance of adequate calcium intake and weight-bearing activities combined with early detection and treatment of specific abnormalities can ameliorate these associated adult morbidities. During the final phase of transition, the pediatric endocrinologist should engage the patient with TS in developing a comprehensive adult care roadmap or 'transition passport', which serves as a powerful educational tool. The aim of refining the transition process is to improve adult outcomes and quality of life for patients with TS.

New and active role of the interstitium in control of interstitial fluid pressure: potential therapeutic consequences

Here we present recent data indicating that the present view of the interstitium as a passive fluid reservoir has to be revised. The connective tissue cells and extracellular matrix have a role in the control of P(if) and a fundamental role in the rapid development of edema in burns and in the initial swelling in inflammation by generating a lowering of interstitial fluid pressure. In this process, the beta1-integrin system seems to provide a common pathway by which the cells can lower as well as raise P(if). Inflammatory swelling can be reversed by endo- and exogenous substances, thereby suggesting that the connective tissue can serve as a novel target for pharmacological intervention. Furthermore, the new knowledge in interstitial physiology on means to reduce interstitial fluid pressure may be of importance for drug delivery into solid tumors, where a high P(if) limits the uptake of therapeutic agents.

Does bullying cause emotional problems? A prospective study of young teenagers

OBJECTIVES

To establish the relation between recurrent peer victimisation and onset of self reported symptoms of anxiety or depression in the early teen years.

DESIGN

Cohort study over two years.

SETTING

Secondary schools in Victoria, Australia.

PARTICIPANTS

2680 students surveyed twice in year 8 (aged 13 years) and once in year 9.

MAIN OUTCOME MEASURES

Self reported symptoms of anxiety or depression were assessed by using the computerised version of the revised clinical interview schedule. Incident cases were students scoring >/=12 in year 9 but not previously. Prior victimisation was defined as having been bullied at either or both survey times in year 8.

RESULTS

Prevalence of victimisation at the second survey point in year 8 was 51% (95% confidence interval 49% to 54%), and prevalence of self reported symptoms of anxiety or depression was 18% (16% to 20%). The incidence of self reported symptoms of anxiety or depression in year 9 (7%) was significantly associated with victimisation reported either once (odds ratio 1.94, 1.1 to 3.3) or twice (2.30, 1.2 to 4.3) in year 8. After adjustment for availability of social relations and for sociodemographic factors, recurrent victimisation remained predictive of self reported symptoms of anxiety or depression for girls (2.60, 1.2 to 5.5) but not for boys (1.36, 0.6 to 3.0). Newly reported victimisation in year 9 was not significantly associated with prior self report of symptoms of anxiety or depression (1.48, 0.4 to 6.0).

CONCLUSION

A history of victimisation and poor social relationships predicts the onset of emotional problems in adolescents. Previous recurrent emotional problems are not significantly related to future victimisation. These findings have implications for how seriously the occurrence of victimisation is treated and for the focus of interventions aimed at addressing mental health issues in adolescents.

Cytochalasin D induces edema formation and lowering of interstitial fluid pressure in rat dermis

The increased capillary fluid filtration required to create a rapid edema formation in acute inflammation can be generated by lowering the interstitial fluid pressure (P(IF)). The lowering of P(IF) appears to involve dynamic beta(1)-integrin-mediated interactions between dermal cells and extracellular matrix fibers. The present study specifically investigates the role of the cell cytoskeleton, i.e., the contractile apparatus of cells, in controlling P(IF) in rat skin as the integrins are linked to both the cytoskeleton and the extracellular matrix. P(IF) was measured using a micropuncture technique in the dorsal skin of the hind paw at a depth of 0.2--0.5 mm and following the induction of circulatory arrest with the intravenous injection of KCl in pentobarbital anesthesia. This procedure prevented the transcapillary flux of fluid and protein leading to edema formation in acute inflammation, which in turn can increase the P(IF) and therefore potentially mask a decrease of P(IF). Control P(IF) (n = 42) averaged -0.8 +/- 0.5 (means +/- SD) mmHg. In the first group of experiments, subdermal injection of 2 microl cytochalasin D, a microfilament-disrupting drug, lowered P(IF) to an average of -2.8 +/- 0.7 mmHg within 40 min postinjection (P < 0.05 compared with control). Subdermal injection of vehicle (10% DMSO in PBS or PBS alone) did not change the P(IF) (P > 0.05). Lowering of the P(IF) was not observed after the injection of colchicine or nocodazole, which specifically disrupts microtubuli in cultured cells. In the second group of experiments, 2 microl of cytochalasin D injected subdermally into rats with intact circulation increased the total tissue water (TTW) and albumin extravasation rate (E(ALB)) by 0.7 +/- 0.2 and 0.4 +/- 0.3 ml/g dry wt, respectively (P < 0.05 compared with vehicle). Nocodazole and colchicine did not significantly alter the TTW or E(ALB) compared with the vehicle (P > 0.05). Taken together, these findings strongly suggest that the connective tissue cells can participate in control of P(IF) via the actin filament system. In addition, the observation that subdermal injection of cytochalasin D lowered P(IF) indicates that a dynamic assembly and disassembly of actin filaments also occurs in the cells of dermal tissues in vivo.

Control of interstitial fluid pressure: role of beta1-integrins

This review has summarized experiments which show that the connective tissue cells can actively modulate the physical properties of the interstitial matrix so that it becomes an "active" participant in transcapillary fluid exchange and thereby interstitial fluid homeostasis. The beta1-integrin system seems to provide a common pathway by which the cells can both raise and lower the interstitial fluid pressure. The experiments with alpha-trinositol and platelet-derived growth factor-BB suggest that the connective tissue can serve as a novel target for pharmacologic intervention in inflammation.

Layilin, a novel integral membrane protein, is a hyaluronan receptor

The actin cytoskeleton plays a significant role in changes of cell shape and motility, and interactions between the actin filaments and the cell membrane are crucial for a variety of cellular processes. Several adaptor proteins, including talin, maintain the cytoskeleton-membrane linkage by binding to integral membrane proteins and to the cytoskeleton. Layilin, a recently characterized transmembrane protein with homology to C-type lectins, is a membrane-binding site for talin in peripheral ruffles of spreading cells. To facilitate studies of layilin's function, we have generated a layilin-Fc fusion protein comprising the extracellular part of layilin joined to human immunoglobulin G heavy chain and used this chimera to identify layilin ligands. Here, we demonstrate that layilin-Fc fusion protein binds to hyaluronan immobilized to Sepharose. Microtiter plate-binding assays, coprecipitation experiments, and staining of sections predigested with different glycosaminoglycan-degrading enzymes and cell adhesion assays all revealed that layilin binds specifically to hyaluronan but not to other tested glycosaminoglycans. Layilin's ability to bind hyaluronan, a ubiquitous extracellular matrix component, reveals an interesting parallel between layilin and CD44, because both can bind to cytoskeleton-membrane linker proteins through their cytoplasmic domains and to hyaluronan through their extracellular domains. This parallelism suggests a role for layilin in cell adhesion and motility.

Inhibition of platelet-derived growth factor receptors reduces interstitial hypertension and increases transcapillary transport in tumors

Most solid malignancies display interstitial hypertension and a poor uptake of anticancer drugs. Platelet-derived growth factor (PDGF) and the cognate tyrosine kinase receptors are expressed in many tumors. Signaling through PDGFbeta receptors was shown recently to increase interstitial fluid pressure (IFP) in dermis after anaphylaxis-induced lowering of IFP. In this study, we show that treatment with the selective PDGF receptor kinase inhibitor, STI571, formerly known as CGP57148B, decreased the interstitial hypertension and increased capillary-to-interstitium transport of 51Cr-EDTA in s.c. growing rat PROb colonic carcinomas. Furthermore, treatment with an antagonistic PDGF-B oligonucleotide aptamer decreased interstitial hypertension in these tumors. PDGFbeta receptors were expressed in blood vessels and stromal cells but not in the tumor cells of PROb colonic carcinomas. Our study indicates a previously unrecognized role of PDGF receptors in tumor biology, although similar effects of PDGF on IFP have been demonstrated previously in the dermis. The data suggest interference with PDGF receptors, or their ligands, as a novel strategy to increase drug uptake and therapeutic effectiveness of cancer chemotherapy.

[Beta1 integrins and edema formation in acute inflammation--new therapeutic possibilities?]

BACKGROUND

The role of the intestitium (the extracellular and extravascular tissue) with regard to transcapillary fluid balance and control of interstitial fluid volume has normally been considered to be a "passive controller".

MATERIAL AND METHODS

This review is based upon literature collected through the authors' own studies and through Medline searches.

RESULTS

Recent studies, however, indicate that the connective tissue cells can actively modulate physical properties of the interstitial matrix, so that it becomes an "active" participant in transcapillary fluid exchange and thereby interstitial fluid homeostasis. The beta 1-integrin system seems to provide a common pathway by which the cells can raise and lower interstitial fluid pressure and thereby regulate the tissue fluid volume.

INTERPRETATION

Experiments in which a new anti-inflammatory agent (alpha-trinositol), platelet-derived growth factor (PDGF), and a prostagladin F2 alpha-analog (latanoprost) modulate interstitial fluid pressure and oedema generation in acute inflammation, suggest that the extracellular matrix can be a target for pharmacological intervention during inflammatory processes.

Fibrosis in undifferentiated (anaplastic) thyroid carcinomas: evidence for a dual action of tumour cells in collagen type I synthesis

The mechanisms involved in stromal reactions and fibrosis in solid malignant tumours are incompletely understood. In the present study, collagen type I production was investigated in tissues and cell lines derived from human undifferentiated (anaplastic) thyroid carcinomas, a highly aggressive, often fibrotic malignancy with mesenchymal phenotype. In situ hybridization showed the expression of pro-alpha1(I) collagen mRNA throughout the stromal part of the tumours. However, immunofluorescence staining using an anti-pro-collagen type I antibody revealed the synthesis of pro-collagen type I protein mainly in stromal cells juxtaposed to nests of tumour cells. In one out of five tissue samples from human undifferentiated thyroid carcinomas, pro-alpha1(I) collagen mRNA expression was also found in a small number of tumour cells. Several well-characterized cell lines established from undifferentiated thyroid carcinomas, two from tumours included in the present study, expressed both pro-alpha1(I) collagen and prolyl 4-hydroxylase mRNA, and three of these cell lines also synthesized native triple-helical collagen type I. Taken together, these data suggest that stromal fibroblasts are the main producers of collagen type I in anaplastic thyroid tumours. The carcinoma cells seem to play a regulatory role, stimulating the synthesis of collagen type I protein in the surrounding stroma by increasing pro-alpha1(I) collagen mRNA translation. However, collagen type I production by the carcinoma cells might also contribute to the marked desmoplasia commonly seen in these tumours.

Lowering of tumoral interstitial fluid pressure by prostaglandin E(1) is paralleled by an increased uptake of (51)Cr-EDTA

High intra-tumoral fluid pressure (TP(IF)) may impair uptake of anticancer drugs into tumors, contributing to poor efficiency in treatment of carcinomas. Here, we demonstrate that lowering of TP(IF) parallels increased transport of (51)Cr-EDTA (m.w. 341) into tumor interstitium. Introduction of 15 microg prostaglandin E(1) (PGE(1)) -methyl ester into the s.c. tissue surrounding transplanted rat colonic (PROb) carcinomas or chemically-induced rat mammary carcinomas, lowered TP(IF) by 30%. Transcapillary transport into the interstitium of PROb tumors quantified by microdialysis increased by 39.6% after PGE(1) treatment 40 min prior to administration of (51)Cr-EDTA (n=6; p<0.05) compared to vehicle (n=10). In mammary tumors, PGE(1) increased transport into the tumors by 86.9% over controls (n=16; p<0.05). Both tumors had well developed stroma containing collagen and hyaluronan. Our data demonstrate that adjuvant treatment with PGE(1) lowers TP(IF), and enhances transport into the tumors. This principle may be of value as adjuvant therapy in treatment of solid malignancies with currently used anticancer drugs.

A bone sialoprotein-binding protein from Staphylococcus aureus: a member of the staphylococcal Sdr family

Staphylococcus aureus bacteria, isolated from bone and joint infections, specifically interact with bone sialoprotein (BSP), a glycoprotein of bone and dentine extracellular matrix, via a cell-surface protein of M(r) 97000 [Yacoub, Lindahl, Rubin, Wendel, Heinegârd and Rydén, (1994) Eur. J. Biochem. 222, 919-925]. Amino acid sequences of seven trypsin fragments from the 97000-M(r) BSP-binding protein were determined. A gene encoding a protein encompassing all seven peptide sequences was identified from chromosomal DNA isolated from S. aureus strain O24. This gene encodes a protein with 1171 amino acids, called BSP-binding protein (Bbp), which displays similarity to recently described proteins of the Sdr family from S. aureus. SdrC, SdrD and SdrE encode putative cell-surface proteins with no described ligand specificity. Bbp also shows similarity to a fibrinogen-binding protein from S. epidermidis called Fbe. A serine-aspartic acid repeat sequence was found close to the cell-wall-anchoring Leu-Pro-Xaa-Thr-Gly sequence in the C-terminal end of the protein. Escherichia coli cells were transformed with an expression vector containing a major part of the bbp gene fused to the gene for glutathione S-transferase. The affinity-purified fusion protein bound radiolabelled native BSP, and inhibited the binding of radiolabelled BSP to staphylococcal cells. Serum from patients suffering from bone and joint infection contained antibodies that reacted with the fusion protein of the BSP-binding protein, indicating that the protein is expressed during an infection and is immunogenic. The S. aureus Bbp protein may be important in the localization of bacteria to bone tissue, and thus might be of relevance in the pathogenicity of osteomyelitis.

Platelet-derived growth factor beta receptor regulates interstitial fluid homeostasis through phosphatidylinositol-3' kinase signaling

Platelet-derived growth factor (PDGF) isoforms lead to mitogenic, survival, and chemotactic responses in a variety of mesenchymal cell types during development and in the adult. We have studied the importance of phosphatidylinositol-3' kinase (PI3K) signaling in these responses by mutating the PI3K-binding sites in the PDGF-beta receptor by gene targeting in embryonic stem cells. Homozygous mutant mice developed normally; however, cells derived from the mutants were less chemotactic and had largely lost their ability to contract collagen gels in response to PDGF. Injection of a mast cell degranulating agent in mice led to a decrease in interstitial fluid pressure resulting in edema formation. In contrast to wild-type mice, mutant mice were unable to normalize the pressure after treatment with PDGF. Taken together, these observations suggest a function for PDGF signaling through PI3K in interstitial fluid homeostasis by modulating the tension between cells and extracellular matrix structures.

Activation of microvascular pericytes in autoimmune Raynaud's phenomenon and systemic sclerosis

OBJECTIVE

To determine the temporal and spatial relationship between platelet-derived growth factor beta (PDGFbeta) receptors, PDGF-AB/BB, and activated pericytes across the Raynaud's phenomenon (RP) and systemic sclerosis (SSc; scleroderma) disease spectrum.

METHODS

Monoclonal antibodies against PDGFbeta receptors, PDGF-AB/BB, and high molecular weight-melanoma-associated antigen (HMW-MAA), a marker for activated pericytes, were used to immunohistochemically analyze serial sections of skin biopsy tissue from patients with RP and from scleroderma patients. To delineate cell-specific PDGFbeta receptor expression, double immunofluorescence-stained sections were analyzed using computer-aided image analysis and confocal microscopy.

RESULTS

PDGFbeta receptor-expressing cells and HMW-MAA-expressing pericytes were found in biopsy samples from autoimmune RP patients and in both early fibrotic and early nonfibrotic scleroderma skin, but not in normal or primary RP or late-stage scleroderma skin. PDGF-AB/BB was expressed within the epidermis, at the epidermal/dermal junction, and by dermal macrophages. Analysis of juxtaposed serial sections revealed an increased frequency of receptor expression in microvessels from autoimmune RP and early scleroderma skin (P < 0.01). Double-labeling studies using confocal microscopy showed that, in vivo, PDGFbeta receptors were predominantly expressed by microvascular pericytes from both autoimmune RP and early scleroderma skin.

CONCLUSION

PDGFbeta receptors are expressed by activated microvascular pericytes in patients with autoimmune RP and in early SSc patients, but not in those with primary RP or late-stage scleroderma. These findings suggest that features of autoimmune RP are distinct from those of primary RP, and that microvascular pericytes may be an important link between chronic microvascular damage and fibrosis.

Signaling via fibroblast growth factor receptor-1 is dependent on extracellular matrix in capillary endothelial cell differentiation

Differentiation of endothelial cells, i.e., formation of a vessel lumen, is a prerequisite for angiogenesis. The underlying molecular mechanisms are ill defined. We have studied a brain capillary endothelial cell line (IBEC) established from H-2Kb-tsA58 transgenic mice. These cells form hollow tubes in three-dimensional type I collagen gels in response to fibroblast growth factor-2 (FGF-2). Culture of IBEC on collagen gels in the presence of FGF-2 protected cells from apoptosis and allowed tube formation (i.e., differentiation) but not growth of the cells. FGF-induced differentiation, but not cell survival, was inhibited by treatment of the cells with an anti-beta1-integrin IgG. Changes in integrin expression in the collagen-gel cultures could not be detected. Rather, cell-matrix interactions critical for endothelial cell differentiation were created during the culture, as indicated by the gradual increase in tyrosine phosphorylation of focal adhesion kinase in the collagen-gel cultures. Inclusion of laminin in the collagen gels led to FGF-2-independent formation of tube structures, but cells were not protected from apoptosis. These data indicate that FGF receptor-1 signal transduction in this cell model results in cell survival. Through mechanisms dependent on cell-matrix interactions, possibly involving the alpha3beta1-integrin and laminin produced by the collagen-cultured IBE cells, FGF stimulation also leads to differentiation of the cells.

Cell interactions with collagen matrices in vivo and in vitro depend on phosphatidylinositol 3-kinase and free cytoplasmic calcium

We have investigated the role of phosphatidylinositol 3-kinase (PI3-kinase) in cellular interactions with collagenous matrices. Platelet-derived growth factor-BB (PDGF-BB) elicited a mobilization of intracellular Ca2+ in pig aortic endothelial (PAE) cells transfected with wild type PDGF beta-receptor. This response was greatly reduced in PAE cells transfected with PDGF beta-receptors mutated at positions Y740 and Y751 to prevent PI3-kinase binding. The experimental drug 1D-myo-inositol 1,2,6-trisphosphate (alpha-trinositol) induced a rapid increase and subsequent oscillations of the cytoplasmic Ca2+ concentration in cultured fibroblasts. This response was not due to an effect of alpha-trinositol on inositol 1,4,5-trisphosphate (IP3) receptors. alpha-Trinositol did not influence PDGF-BB elicited chemotaxis through collagen-coated membranes of PAE cells transfected with the wild-type PDGF beta-receptor, but restored PDGF-BB elicited chemotaxis of PAE cells transfected with the PI3-kinase binding-site mutated PDGF beta-receptor. Collagen gel contraction has been suggested to serve as a model for cellular control of interstitial fluid pressure (PIF) in dermis. The PI3-kinase inhibitors wortmannin (50 nM) and LY294002 (5 microM) inhibited the stimulation of fibroblast-mediated collagen gel contraction by 0.4 nM PDGF-BB. Injection of wortmannin in rat paw skin induced a lowering of PIF, and this effect was abolished in animals pre-treated with alpha-trinositol. Pretreatment of rats with alpha-trinositol abolished the decrease in PIF induced by injecting monoclonal anti-rat alpha 2 beta 1 integrin IgG in rat paw skin. Taken together our data indicate that cell-collagen interactions in vivo and in vitro depend on PI3-kinase, and that this dependence can be bypassed by a drug eliciting intracellular Ca2+ mobilization.

Osteoporosis in the corticosteroid-treated patient with asthma

Osteoporosis affects 40% of white women older than 45 years of age and 15% of white men older than 50 years of age, resulting in approximately 1.5 million annual fractures in the United States. Systemic corticosteroid therapy increases the probability of osteoporosis, even with alternate-day dosing and with dosages sufficiently low so as not to affect the hypothalamic-pituitary-adrenal axis. Inhaled corticosteroid therapy may affect bone density if high-dose therapy is given to select individuals. The potential of increasing osteoporosis with inhaled corticosteroid asthma therapy is a concern because of the availability of more potent inhaled corticosteroid agents and recommendations that inhaled corticosteroid therapy be initiated earlier in the course of asthma. This article provides suggestions, on the basis of the medical literature and consensus of the authors when specific information was not available, for assessing and treating osteoporosis in subjects with asthma. Suggested risk categories are "low risk" (inhaled corticosteroid dosage of < or =800 microg of heclomethasone dipropionate [BDP]/day in adults or < or =400 microg BDP or equivalent in children), "moderate risk" (inhaled BDP >800 microg/day in adults or >400 microg/day in children), and "high risk" (systemic corticosteroid therapy 4 times a year or daily or alternate-day systemic corticosteroid therapy). Dosage of nasal corticosteroid probably should be added to the orally inhaled corticosteroid for total burden of inhaled corticosteroid. Potential treatment strategies based on risk factors and bone density if indicated are offered to assist physicians treating patients with asthma.

Turner syndrome and osteoporosis: mechanisms and prognosis

Despite only limited reports of a greater number of fractures during childhood or adulthood, osteoporosis historically has been described as a feature in Turner syndrome, because of the frequent observation of radiographic osteopenia and the coarse trabecular pattern of the carpal bones on radiographs. The pathogenesis of the skeletal demineralization remains unclear, but the data support the concept of an intrinsic bone defect that is then exacerbated by a number of hormonal factors, including the growth-regulating hormones, the gonadal steroids, and possibly the calcium-regulating hormones. The advent of more refined methods, such as single- and dual-photon absorptiometry and dual energy x-ray absorptiometry, has led to improved insights into bone mineral density (BMD) status in Turner syndrome (TS). A major limitation of these projection methods is that they report areal and not true volumetric BMD, resulting in an underestimation of the true BMD in smaller subjects. In assessing BMD in TS, various methods have been used to eliminate the confounding effect of bone size. Some consistent patterns do emerge in persons with TS who are not treated with long-term growth hormone (GH) or estrogen therapy. A significant deficit in cortical bone commonly appears in childhood and usually is associated with a low bone-turnover state. Significant osteopenia at predominantly trabecular sites develops during mid- to late adolescence and persists into adulthood, when it is associated with increased bone turnover. Preliminary BMD data on patients after long-term GH therapy show an absence of osteopenia. With respect to the impact of long-term estrogen therapy, the BMD deficit in adults with TS who have been treated adequately with estrogen, but who have not been treated with GH, is less than it is in those who have been insufficiently treated or not treated at all with estrogen. The available data indicate that long-term GH treatment during the prepubertal and early to midpubertal years optimizes BMD and improves the prognosis for adequate peak bone mass being achieved after a puberty that, most often, has been induced with exogenous estrogen. Long-term treatment with estrogen and progestin that is initiated during mid- to late adolescence and is continued throughout adulthood appears necessary for a normal peak bone mass to be achieved and the BMD to be preserved well beyond the time of peak bone mass. Additional measures to prevent osteoporosis must be used, such as ensuring adequate calcium intake and ample weight-bearing activities, focusing on preventing injuries and avoiding overtreatment with thyroid hormones. Long-term surveillance with measurement of BMD and of bone turnover in a large TS population into their later adult years is necessary before it can be concluded that the osteopenia observed in TS is a nonprogressive asymptomatic bone defect of no clinical consequences.

Type I collagen synthesis in cultured human fibroblasts: regulation by cell spreading, platelet-derived growth factor and interactions with collagen fibers

Type I collagen protein and pro-alpha 1(I) collagen mRNA levels were investigated in human dermal fibroblasts cultured on substrates which induced distinct morphologies. Induction of type I collagen protein synthesis required cell spreading in monolayer cultures; mere attachment to dishes coated with 2-hydroxyethyl methacrylate (poly(HEMA)) did not suffice. Spread cells or round cells cultured on poly(HEMA) differed in collagen type I production, but pro-alpha 1(I) collagen mRNA levels were similar. Recombinant human platelet-derived growth factor (PDGF)-BB could replace cell spreading as a stimulus for collagen synthesis in cells cultured on poly(HEMA). At later time points, pro-alpha 1(I) collagen mRNA levels were down-regulated, although relatively less than type I collagen synthesis. Type I collagen synthesis by fibroblasts cultured in three-dimensional collagen gels was strongly down-regulated at both the protein and RNA levels. In addition to its capacity to stimulate collagen synthesis, PDGF-BB induced elongation and the formation of long processes by fibroblasts cultured in collagen gels. The stimulatory effect by cell spreading and PDGF-BB on collagen synthesis was inhibited by the phosphatidylinositol 3-kinase (PI3K) inhibitor LY294002. However, inhibition of PI3K only inhibited induction of collagen synthesis by actively spreading cells or by PDGF-BB and did not induce a down-regulation of collagen synthesis in cells which had already spread. These data demonstrate that type I collagen protein synthesis is partly independent of pro-alpha 1(I) collagen mRNA levels but highly regulated by cell shape, although this could be decoupled by PDGF-BB. Both cell shape- and PDGF-BB-induced stimulation of collagen type I synthesis depends on a signalling pathway involving PI3K. Furthermore, levels of pro-alpha 1(I) collagen mRNA in fibroblasts are partly cell shape independent but are down-regulated by fibroblast interactions with native collagen fibers.

Effect of PGE1, PGI2, and PGF2 alpha analogs on collagen gel compaction in vitro and interstitial pressure in vivo

Acute inflammation in skin is accompanied by increased negativity of interstitial fluid pressure (PIF), which will increase capillary fluid filtration and thereby potentiate edema formation. A series of studies indicates that the connective tissue cells in rat dermis are involved in the control of PIF and mediate this response. The present study describes a novel effect of prostaglandin (PG) E1 isopropyl ester, carbaprostacyclin (PGI2 analog), and latanoprost (PGF2 alpha analog) on edema formation and PIF in parallel with their action on the fibroblast-populated collagen gel contraction assay. The prostaglandins were injected subdermally in pentobarbital-anesthetized rats. PIF was measured with a servo-controlled counterpressure system after circulatory arrest had been induced with saturated potassium chloride. Circulatory arrest was induced to limit edema formation that would raise interstitial fluid volume and thereby attenuate a possible increased negativity of PIF. PGE1 (0.91 mM) and carbaprostacyclin (1.28 mM) lowered PIF from a control value of -0.8 +/- 0.4 mmHg to -3.0 +/- 0.4 (P < 0.01) and -3.7 +/- 0.9 (P < 0.01) mmHg, respectively, within 45 min in a dose-dependent manner. Edema formation was measured in separate experiments. PGE1 and carbaprostacyclin significantly increased interstitial fluid volume (extravascular 51Cr-EDTA space) at concentrations as low as 0.1 and 1.1 microM, respectively. Latanoprost had no effect on PIF or edema formation. However, latanoprost reversed, in a dose-dependent manner, an increased negativity of PIF accompanying the anaphylactic reaction to dextran. In the gel contraction assay with human diploid fibroblasts (AG 1518), a corresponding specificity was observed where PGE1 and carbaprostacyclin effectively inhibited gel contraction although latanoprost had no effect. Thus the present data demonstrate a novel effect of prostaglandins and provide further evidence for active modulation of PIF via loose connective tissue cells.

Integrins in thyroid tissue: upregulation of alpha2beta1 in anaplastic thyroid carcinoma

OBJECTIVE

To evaluate the integrin pattern in the normal thyroid gland and in different pathological disorders including malignant tumors, because the aggressiveness of several malignant tumors correlates with alterations in the expression of one or more integrins.

DESIGN

We examined the expression of integrins and E-cadherin immunohistochemically in a large and well-defined sample of normal and pathological human thyroid tissue.

METHODS

Cryosections of 58 thyroid tissue specimens from normal tissue, thyrotoxicosis, nodular goiter, oxyphilic adenoma, follicular adenoma, follicular carcinoma, papillary carcinoma and anaplastic carcinoma, and three lymph node metastases were investigated immunohistochemically using monoclonal antibodies specifically recognizing the integrin beta1-, beta4-, alpha1-, alpha2-, alpha3-, alpha5- and alpha6-subunits, or E-cadherin.

RESULTS

All thyroid epithelial cells expressed integrin beta1- and alpha3-subunits. Immunostaining of the beta4-subunit and the alpha6-subunits was found only in tumors. The staining pattern in the three lymph node metastases from papillary carcinomas did not differ from that in their primaries. Anaplastic carcinomas demonstrated neoexpression of the integrin alpha2-subunit. E-cadherin was detected in all tissues except anaplastic carcinomas.

CONCLUSIONS

Neoexpression of alpha6beta4 was seen in most malignant tumors, whereas alpha2 was exclusively found in anaplastic carcinomas. In the latter, a loss of E-cadherin expression was also seen. These changes in cell adhesion molecule expression strongly suggest an association with the acquisition of proliferative and invasive properties.

Tumor cell and connective tissue cell interactions in human colorectal adenocarcinoma. Transfer of platelet-derived growth factor-AB/BB to stromal cells

Mechanisms underlying stimulation of platelet-derived growth factor (PDGF) beta-receptors expressed on connective tissue cells in human colorectal adenocarcinoma were investigated in this study. PDGF-AB/BB, but not PDGF receptors, was expressed by tumor cells in situ, as well as in tumor cell isolates of low passage from human colorectal adenocarcinoma. In an experimental co-culture system, conditioned medium from tumor cells only marginally activated PDGF beta-receptors expressed on fibroblasts. In contrast, co-culturing of the two cell types led to a marked PDGF beta-receptor activation. Functional PDGF-AB/BB was found to be associated with heparinase-I-sensitive components on the tumor cell surface. PDGF-AB/BB, isolated from heparinase-I-sensitive cell surface components, induced a marked activation of PDGF beta-receptors. Furthermore, co-culturing tumor cells together with fibroblasts led to a sustained activation of PDGF beta-receptors expressed on fibroblasts. Double immunofluorescence staining of tissue sections from human colorectal adenocarcinoma, combined with computer-aided image analysis, revealed that nonproliferating tumor cells were the predominant cellular source of PDGF-AB/BB in the tumor stroma. In addition, PDGF-AB/BB-expressing tumor cells were found juxtapositioned to microvascular cells expressing activated PDGF beta-receptors. Confocal microscopy revealed a cytoplasmic and cell-membrane-associated expression of PDGF-AB/BB in tumor cells situated in the stroma. In contrast, epithelial cells situated in normal or tumorous acinar structures revealed only a cell-membrane-associated PDGF-AB/BB expression. The is vitro and in situ results demonstrate that tumor cells not only facilitate but also have the ability to modulate connective tissue cell responsiveness to PDGF-AB/BB in a paracrine fashion, through direct cell-cell interactions in human colorectal adenocarcinoma.

Integrins and Control of Interstitial Fluid Pressure

The present review summarizes recent information on the physiology of connective tissues, in particular, control of interstitial fluid pressure (Pif) and, thereby, interstitial volume. A combination of classic physiological techniques and techniques from cellular and molecular biology have provided new insights into control of Pif by connective tissue cells and the adhesion receptors anchoring them to structural connective tissue components.

Expression of tissue inhibitor of metalloproteinases TIMP-2 in human colorectal cancer--a predictor of tumour stage

The aim of this study was to investigate whether immunohistochemical staining patterns of tissue inhibitor of metalloproteinases TIMP-2 and matrix metalloproteinases MMP-2 and MMP-9 can be predictors of tumour stage and survival time in colorectal cancer. Frozen tumour sections from 212 patients operated on between January 1987 and November 1990 were investigated. Three mouse monoclonal antibodies--T2-101 against TIMP-2, CA-4001 against MMP-2 and GE-213 against MMP-9--were used. Positive expression of TIMP-2 (a) in basement membranes and (b) diffusely in stroma with (c) subglandular enhancement was found significantly (P < 0.01, P < 0.05, P < 0.05) more often in localized tumours than in tumours with regional or distant metastases. Neither pattern correlated with tumour differentiation. Patterns (a) and (c) correlated with longer survival time (P < 0.05); (b) reached near significance (P < 0.07). When the survival analyses were restricted to potentially cured patients, neither pattern could foretell death from cancer. Positive expression of MMP-2 in tumour epithelium and of MMP-9 in tumour-infiltrating macrophages were both independent of tumour stage and were without correlation with survival time. A large number of MMP-9-positive macrophages correlated (P < 0.05) with poor tumour differentiation, whereas weak or absent epithelial MMP-2 staining reached near significance (P < 0.08). Exploration of TIMP-2 expression is valuable for the discrimination between macroscopically localized and metastatic colorectal cancer, but it cannot predict which of the potentially cured patients are likely to have micrometastases. MMP-2 and MMP-9 stainings are of minor value in staging and prognostic prediction.